This study validated the quasi-induced exposure (QIE) methods used to assess young driver trends. These methods can be used to address broader foundational and applied questions in young driver safety.

The New Jersey GDL decal provision was implemented in May 2010, and this study found that it was not associated with a change in citation or crash rates among NJ drivers under 21 years of age with learner’s permits between January 2006 and January 2012. The findings contrast with previous research that found a significant decrease in the crash rates of drivers with intermediate licenses after the decal provision.

This study looked at licensing age, driving experience, and GDL license phase in relation to crash rates among young NJ drivers. Findings show that teen drivers have a steep increase in crash risk at the point of transition from intermediate to full licensure. These findings support the recommendation to extend the age requirement for the intermediate license phase to age 21.

This study found that 65% of 17-year-olds living in the highest-income zip codes were licensed in the first month of eligibility compared with 13% of those living in the lowest-income zip codes. Moreover, the younger one obtains an intermediate license, the earlier the graduation to a full license.

NJ’s GDL decal provision is associated with a sustained two-year decline in crash rates among intermediate teen drivers. After comparing monthly rates of police-reported crashes in the four years pre-decal and two years post-decal, the crash rate declined 9.5%. More research is needed to understand how these decals may work to reduce teen driver crashes.

Findings show that the Federal Highway Administration (FHWA) licensing data is not accurate when compared to NJ administrative licensing data. Future researchers should avoid using FHWA licensing data and instead encourage FHWA to work with state licensing agencies to improve the accuracy of its data.

Traditional methods for determining crash responsibility may not be accurate since issuance may vary by factors that are independent of fault, such as age and gender. These methods also do not capture driver behaviors that, while not unlawful, are still indicative of fault. An alternative method based on identifying crash-contributing driver actions should be used instead.

Crash involvement of an estimated 1,624 intermediate drivers was prevented in the first year after the NJ GDL decal's implementation, as well as a 9% decrease in the rate of police-reported crashes among intermediate drivers and a 14% increase in GDL-related citations issued to intermediate drivers. States considering implementing decals can look to NJ’s experience to shape their strategies.

This study found that not wearing a seat belt is 121% more prevalent in communities with the largest percentage of people living with 3 or more vulnerability indicators.

Learn about results from a 2022 National Safety Council Road to Zero Coalition Community Traffic Safety Grant awarded to our team in this showcase.